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The spin-wave spectrum of the Jahn-Teller system LaTiO3

Robert Schmitz·Ora Entin-Wohlman·Amnon Aharony·A. Brooks Harris·Erwin Mueller-Hartmann
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Abstract

We present an analytical calculation of the spin-wave spectrum of the Jahn-Teller system LaTiO3. The calculation includes all superexchange couplings between nearest-neighbor Ti ions allowed by the space-group symmetries: The isotropic Heisenberg couplings and the antisymmetric (Dzyaloshinskii-Moriya) and symmetric anisotropies. The calculated spin-wave dispersion has four branches, two nearly degenerate branches with small zone-center gaps and two practically indistinguishable high-energy branches having large zone-center gaps. The two lower-energy modes are found to be in satisfying agreement with neutron-scattering experiments. In particular, the experimentally detected approximate isotropy in the Brillouin zone and the small zone-center gap are well reproduced by the calculations. The higher-energy branches have not been detected yet by neutron scattering but their zone-center gaps are in satisfying agreement with recent Raman data.

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Robert Schmitz, Ora Entin-Wohlman, Amnon Aharony, A. Brooks Harris, Erwin Mueller-Hartmann. 2004-11-23. The spin-wave spectrum of the Jahn-Teller system LaTiO3. https://doi.org/10.1103/physrevb.71.214438

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